US2636161A

US2636161A - Directional horizon indicating instrument

Info

Publication number: US2636161A
Application number: US214400A
Authority: US
Inventors: George W Hoover
Original assignee: Individual
Current assignee: Individual
Priority date: 1951-03-07
Filing date: 1951-03-07
Publication date: 1953-04-21
Anticipated expiration: 1970-04-21

Description

April 21, 1953' G. wndovm 36 DIRECTIONAL HORIZON INDICATING INSTRUMENT Filed March 7, 1951 FIG. 2 FIG. 3

INVENTOR. 650/8 5 M Ham/ER Patented Apr. 21, 1953 UNITED STATES PATENT OFFICE DIRECTIONAL HORIZON INDICATING INSTRUMENT (Granted under Title 35, U. 8. Code (1952),

see. 266) 12 Claims.

The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

This invention relates to improvements in directional horizon indicating instruments, and more particularly pertains to aircraft attitude indicating instruments that portray attitude with respect to the ground in terms of the attitude of a sphere suspended with three degrees of freedom with respect to the instrument face.

A single indicating instrument capable of giving both directional and attitude references through 360 degrees for all flight conditions is a desideratum in aeronautics. Heretofore, it has been conventional to crowd the instrument panel of aircraft further by using two separate instruments for determining the attitude and direction of the aircraft when in flight, the azimuth or directional indicator and the attitude indicator. These two reference indicators are so closely related in actual use that a pilot attempts to get simultaneous readings. This causes confusion and strain in getting a complete reference of the aircraft's attitude and direction with respect to the earth.

Contemporary faster aircraft demand instrument, panel simplification to assure that safety in flight is not jeopardized by the pilots attention being diverted from the field of vision longer than is reasonably necessary. While indicators providing attitude and directional reference in which some of the reference indications operate within limits are known, the present invention combines the full range of pitch, roll and turn information into a single presentation.

The primary object of the invention is to provide a single presentation instrument adapted to register direction, pitch and bank of an aircraft under all flight conditions.

Another object is to provide an instrument of the character described that simplifies interpretation by including a simulated pictorial horizon.

A further object is to provide an instrument of the character described that so introduces pitch, roll and turn information as to. virtually eliminate the eifect of vertigo while flying on instruments.

Still another object is to provide an instrument of the character described adapted to present a larger picture of attitude information than that possible with instruments of like general nature heretofore employed. I

Another object is to provide an instrument of the character described having a horizon indication fixed in relation to the natural horizon and adapted for use for television or other suitable scanning to provide an enlarged horizon display.

Other objects and many of the attendant advantages of this invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein:

Fig. 1 is a cross section through the instrument case and the directional sphere, partly broken away to show the suspension of the various components, showing a preferred embodiment of the invention;

Fig. 2 is a side elevation of the instrument shown in Fig. 1, partly in section and partly broken away to show such suspension; and

Fig. 3 is a front elevation thereof, sectioned and broken away in part to show such relations.

Similar numerals refer to similar parts throughout the several views.

Instrument case II is provided with a face member 13 attached thereto, said case including an integral mounting flange 15 for securing the face member to the case and for attaching the instrument to an instrument panel (not shown). The face member I3 is provided with a viewing window H. A suitable reference marker l8 can be inscribed on said window.

Brackets l9 mount a selsyn motor 2| on the rear wall 23 of the instrument case. Gimbal fork 25 is attached to and driven by said motor 2| through shaft .22, said gimbal fork being adapted to rotate on a fore and aft axis.

Selsyn motors 2'! and 29 are attached respectively to the arms 3| and 33 of the gimbal fork 25. The

respective shafts

35 and 31 of said motors carry a transparent disc or plate 39 which is rotatable thereby on a transverse axis. The periphery of said plate 39 defines the equator of the sphere hereinafter described, and is provided with a lubber line 4|.

Selsyn motor 43 is mounted on plate 39 by means of bracket 45, the shafts 41 and 49 of said motor being driven on a vertical axis through gear train 5|, said shaft 49 extending through a bearing 53 in the center of said plate. Shaft 41 carries plate 55, which mounts the northern hemisphere 51, and shaft 49 carries plate 59, which mounts the southern hemisphere 6|. Hemisphere 5'! is painted with asky effect including a ring of clouds at the 45 latitude to aid in interpretation, and hemisphere 6| is through conductors carried in cable 65, slip rings- 51 mounted on the shaft 22, brushes iii and cable H. Similarly, selsyn motor 25 is coupled to the means for parallax adjustment through con ductors it, slip rings 6?, brushes t9 and cable ii. Selsyn motor i3 is coupled-to theremote source of azimuth intelligence, such as a gyrostabilized magnetic compass, successively through conductorsled'through shaft 35,-s1ip ringslt,

brushes i'i, cable-65, slip rings 9i, brushes 6%!" and cable ll;

Parallax adjustment between reference marker 58 and hemispheres diand 6! is afiorded through a selsyn motor 79, which is mounted on the face member 13 and operated by control knob 8 l. Said selsyn motor 79 is coupled to selsyn 29 through cablefit and selected brushes t9. Manipulation of control knobfii thus offsets the sphere com= prised of elements 5?; 3i: and tifrom the pitch alignment-with the vertical gyro that drives selsyn motor2li For illumination of the sphere, control knob aii 'is mounted on the face member i3 and is adapted to operate a rheostat Bl that is in the circuit of a light 89 carried on plate 59. Said rheostat is coupled to said light through se lected conductors of cable 83 in the manner hereinabovedescribed, and through conductor ii i.

Another method of illumination comprises painting the sphere with a fluorescent paint that provides the light required to show the contrasts necessary for determining altitude 'when activated by ultraviolet light. The ultraviolet lightingsource can be included in the instrument case or can be provided by an outside source. Alternatively, the light can comprise colored fluorescent paint superimposed on oil paint to provide the required pictorial indications when activated by a source of ultraviolet light.

,A switch 9-3 carried on the face member l3 actuates a circuit througha branch of cable 83 that is adapted, when the circuit is closed, to cage the vertical gyro, locking said gyro in a vertical position.

The operation of the subject device in asso'ciation" with conventional aircraft attitude sensing installations provides a single presentation of attitude, including the factors of roll, pitch and'turn.

'Roll motion'of the aircraft about the longitudinal axis causes the vertical gyro of the aircraft to be offset from the vertical position of the vertical gyro case, transmitting a signal from the vertical gyro selsyn to the selsyn motor 2|,

thus rotating the hemispheres ii!- and iii, together with'the plate 39, in the same angle of tor 29-, thus-simultaneously= oifsetting -the two 4 hemispheres 51 and 6!, and the plate 39, from their vertical position with reference to the instrument case H. Such elements thus are effective to indicate the same angle of pitch of the sphere with the case as the aircraft makes with the actual horizon. 7

Turn motion of the aircraft about its vertical axis causes the gyro-stabilized magnetic compass of the aircraft to be offset from its zero position with respect to its case and to actuate a selsyn which, in turn, actuates selsyn motor 43, rotating simultaneously the hemispheres 5i and Bi withreference to the plate 39, thus indicating the headingv of the aircraft.

The'many advantages of this instrument are evident. There is combined in a single presentation, in a single integrated instrument, the information heretofore indicated by two separate and distinct instruments. Accordingly, this instrument reduces the amount of eye movement required by the pilot to obtain all of the information required to determine the attitude of the aircraft, thusreducing strain, fatigue and the."

likelihood of'confusion in interpretation. Addi'-' tionally, the device simulates-the flight conditions with respect to the'attitude in pictorial form, a medium that is easier for a pilot to interpret than theconventional simulated type of presentation.

Obviously many modifications and variations In an aircraft having'an instrument panel and roll, pitch and turn sensing devices, an'attitude indicating instrument comprising-an instrument case having a viewing window adapted to be mounted on such panel, a sphere comprising a disc and upper and lower hemispheres rotatable relative said disc suspended in said'case, and means responsive to saidsensing devices to rotatesaid sphere "with three degrees of freedom with respect I to said window.

2. In an aircraft having an instrument panel and roll, pitch and turn sensing devices, an at titude indicating instrument comprising an' in-' strument case having a viewing window adapted to be mounted on such panel, a sphere comprising a disc and upper and lower hemispheresrotatable relative said discsuspended in said case, means responsive to said roll and pitch sensing" devices to rotate said sphere on its roll and pitch axes, and means responsive tofsaid turn sensing device to rotate said hemispheres relativesaid' disc.

3. In an aircraft having an instrument panel and roll, pitch andturn sensing devices, an attitude indicating instrument comprising an in'-- strument case having a viewing window adapted to be mounted on'such panel, a sphere comprising a disc and upper and lower hemispheres rotatable relative said disc suspended in said-case,

means responsive to said rolland pitch axes, and

means responsive to said turn sensing device-to rotates said hemispheres relativesaid disc.

4. Inan airc'rafthaving an instrumentpanet and roll, pitch and turn sensing devices, an at titude indicating instrument comprising'an instrument case having a viewing window adapted to be'mounted insuch panel, a sphere compr'ising a disc and'upper and lower hemispheres rotatable relative said disc suspended in said-case;

It -is therefore to be means responsiveto said roll and pitch sensing devices to rotate said disc on its roll andpitch axes, and means mounted on said disc responsive to said turn sensing device to rotate said hemispheres relative said disc.

5. In an aircraft having an instrument panel and roll, pitch and turn sensing devices, an attitude'findicating instrument comprising an instrument case having a viewing window adapted to be mounted on such panel, a sphere comprising a disc'and upper and lower hemispheresrotatable relative said disc, a gimbal fork journaled in said case for rotation on a fore and aft or roll axis, said disc being carried by said fork and being rotatable thereon on a transverse or pitch axis, means responsive to said roll and pitch sensing devices to rotate said disc on its roll and pitch axes, and means mounted on said disc responsive to said turn sensing device to rotate said hemispheres relative said disc.

6. In an aircraft having an instrument panel and roll, pitch and turn sensing devices, an attitude indicating instrument comprising an instrument case having a viewing window adapted to be mounted on such panel, a sphere comprising a disc and upper and lower hemispheres rotatable relative said disc, a gimbal fork journaled in said case for rotation on a fore and aft or roll axis, said disc being carried by said fork and being rotatable thereon on a transverce or pitch axis, a first selsyn motor responsive to said roll sensing device to rotate said disc on its roll axis, a second selsyn motor responsive to said pitch sensing device to rotate said disc on its pitch axis, and a third selsyn motor mounted on said disc and responsive to said turn sensing device to rotate said hemispheres relative said disc.

'7. In an aircraft having an instrument panel and roll, pitch and turn sensing devices, an attitude indicating instrument comprising an instrument case having a viewing window adapted to be mounted on such panel, a'sphere representing the earth and comprising a disc and upper and lower hemispheres rotatable relative said disc, a lubber line inscribed on the periphery of said disc, indicia of azimuth inscribed on the periphery of one of said hemispheres proximate the edge thereof adjacent said disc, a gimbal fork journaled in said case for rotation on a fore and aft or roll axis, said disc being carried by said fork and being rotatable thereon on a transverse or pitch axis, a first selsyn motor responsive to said roll sensing device to rotate said disc on its roll axis, a second selsyn motor responsive to said pitch sensing device to rotate said disc on its pitch axis, and a third selsyn motor mounted on said disc and responsive to said turn sensing device to rotate said hemispheres relative said disc.

8. In an aircraft having an instrument panel and roll, pitch and turn sensing devices, an attitude indicating instrument comprising an instrument case having a viewing window adapted to be mounted on such panel, a reference marker inscribed on said window, a sphere representing the earth and comprising a disc and upper and lower hemispheres rotatable relative said disc, a lubber line inscribed on the periphery of said disc, indicia of azimuth inscribed on the periphery of one of said hemispheres proximate the edge thereof adjacent said disc, a gimbal fork journaled in said case for rotation on a fore and aft or roll axis, said disc being carried by said fork and being rotatable thereon on a 6 transverse or pitch axis, a first selsyn motor responsive to said roll sensing device to rotate said disc on its roll axis, a second selsyn motor responsive to said pitch sensing device to rotate said disc on its pitch axis, and a third selsyn motor mounted on said disc and responsive to said turn sensing device to rotate said hemispheres relative said disc.

9. In an aircraft having an instrument panel and roll, pitch and turn sensing devices, an attitude indicating instrument comprising an instrument case having a viewing window adapted to be mounted on such panel, a sphere comprising a disc, a bearing in the center of said disc carrying a shaft normal to the plane of said disc, and a pair of hemispheres mounted on said shaft for rotation relative said disc, a gimbal fork journaled in said case for rotation on a fore and aft or roll axis, said disc being carried by said fork and being rotatable thereon on a transverse or pitch axis, means responsive to said roll and pitch sensing devices to rotate said disc on its roll and pitch axes, and means mounted on said disc responsive to said turn sensing device to rotate said hemispheres relative said disc.

10. In an aircraft having an instrument panel and roll, pitch and turn sensing devices, an attitude indicating instrument comprising an instrument case having a viewing window adapted to be mounted on such panel, a sphere comprising a disc, a bearing in the center of said disc, a pair of shafts carried by said bearing normal to and respectively above and below the plane of said disc, and having a hemisphere mounted on each of said shafts for rotation relative said disc, a gimbal fork journaled in said case for rotation on a fore and aft or roll axis, said disc being carried by said fork and being rotatable thereon on a transverse or pitch axis, means responsive to said roll and pitch sensing devices to rotate said disc on its roll and pitch axes, and means mounted on said disc responsive to said turn sensing device to rotate said hemispheres relative said disc.

11. In an aircraft having an instrument panel and roll, pitch and turn sensing devices, an attitude indicating instrument comprising an instrument case having a viewing window adapted to be mounted on such panel, a sphere comprising a disc and upper and lower hemispheres rotatable relative said disc, a gimbal fork journaled in said case for rotation on a fore and aft or roll axis, said disc being carried by shafts in the arms of said fork and being rotatable thereon on a transverse or pitch axis, a first selsyn motor responsive to said roll sensing device to rotate said disc on its roll axis, a second selsyn motor responsive to said pitch sensing device to rotate said disc on its pitch axis, and a third selsyn motor mounted on said disc, coupled to said turn sensing device by conductors passing through said disc and one of said shafts to rotate said hemispheres relative said disc.

12. In an aircraft having an instrument panel and roll, pitch and turn sensing device, an attitude indicating instrument comprising an. instrument case having a viewing window adapted to be mounted on such panel, a sphere comprising a disc and upper and lower hemispheres rotatable relative said disc, a gimbal fork carried on first shaft journaled in said case for rotation on a fore and aft or roll axis, said disc being carried by shafts in the arms of said fork and being rotatable thereon on a transverse or pitch axis, a first selsyn motor coupled to said roll sensing device to rotatek said discron 1 its rolliaxis; a: secondcselsynx motor:- coupled to" said i pitch" sensing device through conductorscarried by one of said arms}. slip rings carried on said firstshaft and brushes in engagement with said-slip rings to 'rotate saiddisc :onit's' pitch -axie and a third selsyn' motor mounted on: said disc, coupled to said turn'sens ing device by conductors" passing' threugh said disc, on'e'of the shafts in Said'ari'nS, sli'p rings thereon,- brushes in engagement therewith, con

ductors carried 'byoneof said arms; slip rings carriedon. said fir'st shaft "and brushes inen'gage ment titherewith' to; rotate i'saidihemisph'eres rela tivesaiddisc';

GEORGE W; HOOVER;-

References Cited -in the fi1e of this patent--